Tomato russet mite Aculops lycopersici (Massee)(Acari: Eriophyidae): A new serious pest of tomato in the Sudan
2006
Abdalla, T.E., Agricultural Reserach, Wad Medani (Sudan), Crop Protection Research Centre, Entomology Section
In the winter season of 2005/06, farmers from the irrigated Gezira and the banks of the Blue Nile and Rahad River (Sudan) complained of a sudden wilting, drying and shedding of tomato leaves and death of whole plants in their fields. The phenomenon, named by the farmers as (Asala Nashfa), seems to have widely spread at these areas and the given name was stemmed from their beliefs that the incidence looks a lot like aphids damage, but without honeydew formation. In response, surveys on 11 to¬mato fields (sites) were immediately organized during March 2006; three sites at Um Sunut, two at each of Fadasi El-halimab and El-gregrib and one at each of the Rahad River, Taiba, Fadasi El-amrab and Gezira Research Farm. The objectives of this survey were to determine the causal agent of the phenomenon and its host range, to quantify the severity and extent of damage and the control attempts taken by the farmers. The symptoms observed at the fields were purplish yellow rusty color of the tomato leaves, silvering of the undersurface of the lower ones, curl¬ing longitudinally inward of their upper surface, wilting, desiccating, she¬dding and eventually death of the whole plant. The damage starts at the base of the plant and spreads upward over stems and leaves. Branches tu¬rned bronze or rusty and cracked in longitudinal direction. Fruits became bronzed and their thin skin turned coarse, some were cracked longitudin¬ally and their sizes were severely reduced. Loss of foliage resulted in exposing the tomato fruits to sunburn.Samples of tomato plants (Lycopersicon esculentum) were taken to the laboratory and examined under the stereomicroscope at 45X magnification. Large numbers of eggs and active motile stages of minute living organisms were observed in the leaves
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